From generation to generation, iPods change, and so do iSkin's cases: the Toronto, Canada-based company has steadily continued evolving past its early days of simple, single-layer silicone rubber skins, and into increasingly complex and protective designs. iSkin's most recent feats: the release of eVo4 Duo for iPod classic ($35), Duo for iPod nano 3G ($30), and iSkin for iPod nano 3G ($30), each somewhat new and somewhat familiar to fans of its prior products.

Each of these three cases is based upon the same general concept: the majority of the iPod’s body is covered with a clear frosted layer of silicone rubber, with a hard secondary layer of plastic protecting the screen and parts of the sides. Thanks to unusually precise control over the thickness of each material at various points on the iPod, the combined layers enable iSkin to do what pure rubber or pure hard plastic cases cannot, namely, to provide complete full- or part-time protection for almost all of the iPod’s surfaces, without compromising at all on screen or Click Wheel access.

eVo4 Duo and Duo for iPod nano differ from iSkin for iPod nano in one major way: the Duos use partially colored, metallic-flecked hard plastic with a clear rubber skin, while iSkin for iPod nano comes with one entirely clear hard plastic faceplace and three colored rubber skins. eVo4 Duo comes in either silver, black, pink, crimson red, blue, or brown; the nano Duo version also comes in purple and shifts its red to a brighter version. iSkin sells iSkin for iPod nano in a Groove Pack with clear frosted, opaque white, and opaque black skins.

Pack-ins are largely the same from model to model. Each of the cases comes with a detachable, ratcheting hard plastic belt clip and a rubberized insert to fill the holes in the case should the clip be removed. Duo for iPod nano, unlike the other models, also comes with one of iSkin’s adjustable lanyard necklaces, which enables you to wear the nano upside down from your neck. Like the clips, the necklace is easy to attach and detach, but holds the iPod securely on your body even when jostled.

Generally speaking, all three of the cases performed exactly as expected—quite well—in our testing. Initially, we had trouble using the butterfly-style side clips that hold the hard plastic Visor faceplaces on each case; while it’s easy to get one set of clips on the iPod, the other side never mounts perfectly the first time you try, and requires a little wiggling of the silicone rubber before the pieces integrate properly together. Similarly, the silicone rear inserts that replace the hard plastic belt clip take a little work to line up with the interior of the case, but with some slight tugs, everything comes together just fine.

Notably, the cases’ hard face protectors offer some real advantages over cheaper solutions we’ve tested: they’re not easy to scratch, have a bit of extra shock absorbtion, and don’t distort the contents of the iPods’ screens in any way. iSkin has done a very good job of keeping the screens clear while coloring the rest of the Duo plates, a precision task that other companies routinely screw up with uneven, wavy lines. Consequently, eVo4 Duo and Duo for iPod nano look especially professional; the standard iSkin for iPod nano looks a bit more common, but makes up for its identical pricing by offering more rubber color options in the box.

iSkin’s only misses in the design of all three of the products are arguably small ones. For some reason, both cases use part-time rubber covers for the iPods’ headphone and Dock Connector ports, and full-time covers for their Click Wheels, but offer no coverage for their Hold switches—a trivial, but surprising omission. The Dock Connector and headphone port holes are on the small side, but thanks to the pliability of silicone, they expand to accommodate virtually any accessory you might want to connect. The only limitation: in the 160GB iPod classic Duo case we tested, the bottom cover made the case unusable with Universal Docks. As such Docks have become a lot more common over the past couple of years, incompatible cases have become less desirable in the process. Your option with such accessories is either to pull the case on and off all the time—a hassle with the multi-piece eVo4 Duo—or modify the case to make it compatible. iSkin really should have designed around this issue.

A last omission, the absence of a video stand of some sort, may or may not bother you as a user. Just like the Universal Dock support, some of the best $30-35 cases out there have come to include this as a feature, like iSkin’s past Claro cases did. If this feature matters to you, you’ll need to look elsewhere for an iPod nano solution, or consider Claro instead if you have the iPod classic. For the price, we’d really have preferred to see this included in the Duo cases.

Relative to the company’s earlier products and its current competitors, each of the Duos and iSkin for iPod nano remain highly recommendable case options. While they’re not cheap, they generally avoid coming across as overpriced, a little tacky, or under-thought like the $40 Revo for iPhone, and they offer such significant protection and color options that they’re hard to fault in either category. While the nano version of Duo takes a little step down in distinctiveness from last year’s model thanks to its lack of a colored Click Wheel dot, and also loses the Universal Dock insert that came with the prior version—the reasons it misses the flat A mark the prior version received—it’s still a great case, and the classic version’s lack of Universal Dock functionality is its single biggest blemish. Unless you’re on a really tight budget, or these factors are major in your mind, consider these to be extremely strong contenders for your iPod classic or nano protection dollar.

Editors' Note: iLounge only reviews products in "final" form, but many companies now change their offerings - sometimes several times - after our reviews have been published.
This iLounge article provides more information on this practice, known as revving.